Induction-motor.



J. L. JOHNSON. INDUCTION MOTOR. APPLIOATION FILED FEB.14, 1910.

Patented Sept. 12, 1911.

UNITED s'rAtrns rATENT onnrcn JOHN L. JOHNSON, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO ALLIS-CHALIMEBS COMPANY, A CORPORATION OF NEW JERSEY.

, INDUCTION-Moron.

Specification of Letters Patent.

Application filed February 14, 1910.

Patented Sept. 12, 1911.

Serial No. 543,876.

i'iecting the rotor bars to short-circuitingi rings of rotors having squirrel cage windings.

The object of my invention is to provide a connection for the conducting bars and short-circuiting rings which will be inexpensive, simple and effective, and which will permit parts of the rotor to be assembled more easily and quickly than heretofore. v

In carrying out my invention I connect the rotor bars to .short-circuiting members, which by a relative movement cause the rotor bars to be wedged in said short-circuiting members, effecting good electrical connections.

My invention further consists in certain novel details of construction and combina tion and arrangement of parts to be described in the specification and particularly pointed out in the appended claims lnthe accompanying sheet of drawings, Figure l is a longitudinal elevation, partly in section, of a squirrel cage induction motor embodying my invention. Fig. 2 is an enlarged fragmentary side View of a shortcircuiting ring equipped with my invention; and Fig. 3 is a sectional view taken substantially along the line of Fig. 2.

Upon the shaft of a squirrel cage induction motor is mounted a spider 11 which consists essentially in a hub 12, radial arms 13 and riml i on which is mounted a laminated core The core is provided with the usual slots in which are mounted bars .are in electrical contact. These adjacent annular member-sure provided with a plurality of sets of openings the holes of each set registering with each other for the re; ccption of the rotor bars.

Various means may be employed for the purpose of producing a relative circumterential adjustment of the members 18 and 19 of each short-circuiting ring, but I prefer to employ a construction in which each of the annular shortcircuiting memhersis provided with an inwardly extending lug, designated as 21 on member 19 and as 22 on member 18 respectively. These lugs occur in pairs, overlap each other, and are circmnterentially spaced. One of the lugs is provided with a tapped portion 23 which receives a screw 24, the end of: which screw engages the overlapping lug 21 of the ad jacent short-circuiting annular member. The screw 2% is provided with a loclcnut 25 for securing the annular short-circuiting members in any desired relative position.

The ends of the rotor bars are provide(l with cross-cut slots or grooves 26. The corners of the ends of the rotor bars are cut away forming grooved portions 27. \Vith this arrangement portions 28 and 29 of the rotor bars formed by the cross cuts,

extend slightly beyond the other portions of said bars. lVhen the rings are forced onto the rotor bars so that the openings 20 receive the said bars the latter engage the rings tightly. The cross cut grooves 26 of the rotor conductors may be provided with some yieldable material 30, such as asbestos, or similar substance springing the rotor bars and retaining them in practically per tectclcctrical connection with the shortcircuiting rings. The screw 24 is then forced through the threaded portion 23 of the lug :22 so that the end of the screw engages the overlapping lug 21 of the adjacent annular member on the short eircuiting ring. This screw may be drawn up causing a relative motion between the annular short-circuiting members 18 and 19 in suclr a manner as to clamp tightly the rotor bars in the shortcircuiting rings. that the projecting portions 28 and 29 of the ends of the rotor bars 'will be pressed tightly against the sides of the openings -20 in the short-circuiting rings causing effective and efiieient connections between the short-circuitmg rings and the rotor bars. The desired degree of tightr ss and rigidity between the connections of the It is seen short-circuiting rings and the bars may be made to vary at will by adjusting the screw 24 and when the proper degree of tightness is reached the annular members may be firmly held in position by the lock-nut Surrounding the rotor a stator, which, is provided with a laminated core 31. provided with the usual alternating current winding or windings having end. turns which extend beyond'the core in the usual manner. The rotor constructimi is simple, inexpensive and eiiective and may be applied to machines of any size.

It is evident that there may be many modifications of the precise form herein shown and described, and I aim in my claims to coverall such modifications of the invention which do not involve a departure from the spirit and scope oi same.

What I claim as new is 1. In induction motor, a rotor having a plurality of conductor bars, a conducting ring comprising a plurality of independently movable annular members ror clamp ing the bars between said members when one "of said members is moved, and means for regulating the effective clamping of said bars.

2.- In an induction motor, a squirrel cage rotor having a plurality oi conductor bars, a conducting ring comprising a plurality of annular members at each end of the motor for short-circuiting'the bars, and means tor causing a relative motion between said annular members to wedge said bars.

3. In an induction motor, a squirrel cage rotor having a plurality of conducting bars provided with slotted or grooved end portions, conducting rings comprising a plurality of members at each end of the rotor for short-circuiting the bars, yieldable material located in the slotted or grooved end portions of said bars, and means located on said members for causing a relative motion between said members to wedge said bars.

4. In an induction motor, a squirrel cage rotor having a plurality of conducting bars, a conducting ring comprising a plurality oi members at each end of the rotor for short circuiting the" bars, lugs mounted on said members and occurring in pairs, and means engaging said lugs'for causing a relative movement of said members to clamp said bars in said short-circuiting rings.

5. In an induction motor, a rotor having a plurality of conductor bars, a conducting ring comprising a plurality of members having overlapping lug portions and located ateach end of the rotor for shortcircuiting the bars, screws engaging said lugs to cause a relative movement. between said members to clamp said. bars in said short-circuiting rings, and means for lockmg sa' dscrews to retain said embers in any desired position.

' 3. In an induction motor, a squirrel cage rotor having a plu 'ality oi conducting bars, a conducting ring comprising a plurality oi members in juxtaposition at each end ol' the rotor for short-circuiting the bars, said members being provided with radially oxtcnding integral projections, means engaging said projections for causing a relative movement of said members to clamp said bars in said short-circuiting rings.

7. In an induction motor, a squirrel cage rotor having a plurality of conducting bars, a conducting ring comprising a plurality of annular members provided with registering openings and located at one end of the rotor for short circuiting the bars, and means cooperating to cause a relative movement of said members to clamp said bars in. the openings of said short-circuiting rings.

8. In an induction motor, a squirrel cage rotor havinga plurality of conducting bars provided with slotted end portions, a shortcircuiting vring comprising a plurality of adjacent annular members having registering holes for the reception of said bars, yioldable material located in said slotted portions, and means for causing a relative movement between said annular members for clamping said bars in said short-circuitmg rings.

9. In an induction motor, a rotor having a plurality of conducting bars, and a shortcircuiting ring engaging said bars and having relative movable adjustable parts for clamping said bars,

10. In an induction motor, a rotor having a plurality of conducting bars, and a shortcircuiting ring engaging said bars and having circumferentially movable parts for clamping said bars.

11. In an induction motor, a rotor having a plurality of conducting bars with resilient end portions, and a short-circuiting ring engaging at all times said end portions and having relatively movable parts tor clamp ing said bars.

1 In an induction motor, a rotor having a plurality of conducting bars with resilient end portions, and a short-circuiting ring ongaging said end portions and having circui'nterentially adjustable parts for clamping said bars.

13. In an induction motor, a rotor having a plurality of conducting bars with resilient end portions, and a short-circuiting ring ongaging at all times said end portions and having a plurality of parts, one oi. said parts being adjustable.

V 14-. In an induction motor, a rotor having a plurality of conducting bars with resilient end portions, and a short-circuiting ring engaging said end portions and having rela tively movable parts for clamping simultaneously all of said conducting bars.

15. In an induction motor, a rotor having a plurality of combating bars with resilient end portions, and a short-circuiting ring engaging said end portions and having (211'- eumferentially adjustable parts for elainp- I ing simultaneously all of said conducting bars.

16. In an induction motor, a' rotor having a plurality of conducting bars with slots or grooves in the ends thereof, and a short eii'euitin rin en a in the slotted or G 4 b b D grooved ends of Said bars and having relatively movable parts elamping said conductng bars.

18. 111 an JlUlLlCLlOll motor a rotor having a plurality of conducting bars, and a shorteireuiting ring engaging said bars and having relatively movable and adjustable parts for clamping simultaneously all of said bars. 1.). In an induction motor, a rotor having a plurality of conducting bars, a short-(ircuitinpf ring engaging said bars and ha ving relatively movable parts for clamping :-:imultaneously all of said liars, and means for adjusting the efi'eetive clamping action of said relatively movable parts.

Milwaukee, Wiseonsin, February 1910. In testimony whereof I a'tlix my signa ture in the presence of two witnesses.

JOHN L. JOHNSON.

\Vitnesses:

Cnivs. L. BYRON, Ron. E. S'roLn. 

